Detection of chemical vapours, such as toxic industrial chemical vapours and chemical warfare agent vapours, can be beneficial for the health and safety of factory workers at industrial sites as well as for emergency services and military personnel. Detection of these vapours can be used to warn and alert people so that they can clear a hazardous area, and/or seek appropriate medical attention where there has been a dangerous level of exposure.
Various forms of equipment exist for the detection of vapours, but many of these lack the sensitive, timely response and accuracy required to warn people of chemical threats. For example, large laboratory instruments can detect chemical vapours but rely on techniques such as gas and liquid chromatography. While these are sensitive and wide ranging in detection scope, these devices are large and difficult to transport. Furthermore, they often require appropriately trained staff to operate them, and often require significant setup time in the form of sample preparation.
An alternative technique is the use of laser based technologies to interrogate the atmosphere for chemical vapours at distances out to 4 to 5 km. These techniques are capable of identifying individual chemical species using infrared or raman techniques. However, the required instrumentation is not easily portable, and results can be affected by atmospheric conditions.
There are some portable devices for chemical vapour detection available. These may be miniaturised active electronic devices, which may include gas chromatographs, mass spectrometers, ion mobility spectrometers, flame photometers, photoionization detectors, infrared spectrometers and raman spectrometers, or passive devices which generally work on the principle of colour change chemistry.
The active devices are often prone to contamination, which can result in significant instrument down-time and may limit the functions of the device whilst the devices are in use. Active devices may also impart a logistical burden.
The passive devices generally have a lower logistical burden, being lightweight and portable, requiring no power and very limited user training, but can be insensitive, slow to react, and may require user intervention to sample based upon good colour vision and best judgement. False positives or negatives may occur as a result of the outputs being subjective to the user even with perfect colour vision. As a result, low but harmful levels of chemical vapour can go undetected or a false positive may be perceived.
It is desired to address or ameliorate one or more shortcomings or disadvantages associated with prior methods, systems, devices and applications for use in relation to the detection of chemical vapours, or to at least provide a useful alternative thereto.
Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each claim of this application.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.